A new Habitat for Humanity-built home is a net producer of energy, having met and exceeded its zero-energy goal.

A zero-energy home (ZEH) is designed to produce as much energy as it consumes over the course of a full year. The home uses the utility power grid for storage—delivering energy to the grid when the PV system is producing more energy than is being used in the home and drawing from the grid when the PV system is producing less energy than is needed in the home. This approach eliminates the need for battery storage in the home, thereby reducing the cost, complexity, and maintenance of the solar-electric system.
Reaching zero energy within the affordable housing sector in cold climates can be a challenge. With the zero-energy goal in mind, we designed a 1,200 ft2, three-bedroom Denver zero-energy home that carefully combines envelope efficiency, efficient equipment, appliances and lighting, and passive- and active-solar features to reach the zero-energy goal. The home was designed using an early version of the BEopt building optimization software, a computer program designed to find optimal building designs along the path to zero net energy. Additional analysis was provided by DOE-2, a widely used and accepted freeware building energy analysis program that can predict the energy use and cost for all types of buildings. ...